X error BadWindow inside gdk_window_add_colormap_windows

I've been looking to this function source and I think the error is that isgiving the toplevel window to the X, obtained with gdk_window_get_toplevel.Probably the problem is that I'm doing some stuff with clutter andoffscreens so I think that the toplevel window should be obtained throughthe get_effective_toplevel function.

I can not easily confirm this because I'm using gtk 2.18 and I need todownload / upgrade lots of libraries in order to compile gtk 2.22, to usethe get_effective functions.

I would like if anyone can confirm this as a bug. I'm afraid I can not do asimple example code to reproduce the problem, but I can confirm that it onlyfails with using an rgba visual in the gtk widget instead of the default rgb